THE CANADIAN ENTOMOLOGIST. 65 



acter, as grasshopper colours often are — and in the case of the Acrididre 

 this can only be done by twisting their hind legs about. Such a motion 

 would necessarily result in friction between the femur and the tegmina, 

 friction in irritation and increased growth, and this growth is the sound 

 organ. 



An interesting analogy which he does not mention is found in the sub- 

 family, CEdipodime. Lugger (4), in describing the (Kdipodime, said : 

 " The insects belonging here are mostly large and showy, often possessing 

 bright-red, yellow or even blue wings, with black bands. Nearly all the 

 bright-coloured locusts found in the United States belong to this subfamily; 

 most of them are very conspicuous objects in flight, when they show their 

 colour, which is at other times entirely hidden. (Edipodinae are also very 

 noticeable on account of the rattling noise which the males of most species 

 produce in flight." The connection here between sound and something 

 to be called attention to is quite marked, and while it is about as hard to 

 tell which came first — colour or sound — as it is in the proverbial case of hen 

 or egg, doubtless Portchinsky would say that the sound was originally 

 caused by the vigorous beating of the insect's wings in its amorous display, 

 and is as much a secondary matter as the femora-tegminal stridulation. 



We know that under sexual excitement many insects constantly 

 vibrate their wings, expanding and contracting them, and swell their body 

 to its fullest extent. It is easy to suppose that formerly male crickets, 

 having no bright colours to display, made the most of such motions, 

 elevated their tegmina and nervously vibrated them. The tegmina of 

 the two sides would necessarily rub together, and the result would be the 

 same as in the case of the Acrididse, except for the position of the organs. 

 Of course, if sounds are of any value at all in sexual selection, better 

 sounds are of more value, and so these males, possessing wings well fitted 

 for producing a noise, would win and transmit their exceptional characters. 

 The same applies to the Locustidse. 



But passing to the other groups, we find that sounds are not always 

 concerned with love-making. In a recent journal (5) Babb has described 

 the stridulation of Passalus cornutus. In this case the abdomen is raised, 

 rubbing against the wings when the insects are disturbed. Both males 

 and females stridulate, and he was "led to the conclusion that it is 

 evidence of the insect's displeasure at being disturbed, and not a sexual 



(4) Third annual report of the Entomologist of the University of Minnesota. 



(5) Entomological News, Vol. XII., No. 9. Nov.. 1901. 



